Apartment Security
If a roommate has moved out and handed back their keys, rekeying the cylinder is usually the right move - it is faster and cheaper than replacing the lock and it kills every copy of the old key at once. Two things come first, though. Check what your lease says about changing locks and whether your landlord needs to be notified or given a key. And be certain the person has actually moved out rather than simply left for a while, because in New York City locking out someone who still lawfully occupies the apartment is a serious matter with its own law attached.
These get used interchangeably and they are not the same job. Rekeying means a locksmith opens the cylinder, changes the internal pins so the old key no longer works, and cuts you new keys. The lock stays on the door. Replacing means the hardware comes off and new hardware goes on.
For a roommate situation, rekeying is almost always the answer. The lock is not broken, you are not upgrading security, and the only thing you need to change is which key opens it. It is the cheaper job and in most apartments it is a short visit. See what rekeying actually involves and the full comparison of rekeying versus replacing.
Replacing makes sense in a narrower set of cases: the lock is worn, sticking or already failing, the cylinder is a cheap one you were going to upgrade anyway, you want a restricted keyway so keys cannot be copied, or you are moving to a keypad or smart lock. If the lock already gives you trouble - a key that needs jiggling, a bolt that catches - do the replacement now rather than paying for a rekey and then a replacement eight months later. See the signs a lock is due for replacement.
This is the step New Yorkers skip, and it is the one that causes problems. The apartment entry door is rarely entirely yours to change on a whim.
There is an important line here, and it is worth being plain about. If the person has genuinely moved out - belongings gone, keys returned, everyone agrees they are gone - changing the locks is routine housekeeping. If they have not, it is not.
New York City's unlawful eviction law protects people who lawfully occupy a dwelling, and the protection is not limited to whoever signed the lease. Someone who has lived in the apartment for 30 days or more generally cannot be put out by changing the locks, removing their property or cutting off services; that requires a court. A roommate in the middle of a dispute, a partner during a breakup, or someone who left most of their things behind is a situation to get advice on before calling a locksmith - not after. Our article on what to do when locks are changed on an occupant explains how that law reads from the other side.
This is general information rather than legal advice. If there is any disagreement about whether the person still lives there, speak to a tenant attorney or a housing advocate first. A reputable locksmith will also ask who lives in the apartment and will not help lock out a current occupant - that is a question we are supposed to ask, and a refusal to ask it is a warning sign about the company, not a convenience.
We rekey apartment cylinders across the five boroughs, usually in a single short visit, and we will tell you honestly when a rekey is enough and when the hardware should be replaced instead. Licensed NYC locksmith, NYC DCA #1362785-DCA.
This is the part almost everyone forgets. In a New York building, the apartment key is one credential among several, and rekeying the entry cylinder does nothing to the rest.
The reason to rekey rather than simply collect keys is that you cannot count copies. A key that lived in a shared apartment for two years has likely been duplicated at least once - for a partner, a dog walker, a family member visiting, or just as a spare that ended up in a drawer. None of that is sinister. It is simply the reason a returned key is not the same as a closed door.
Rekeying resolves all of it in one step, because every copy of the old key stops working regardless of who holds it. If you want to stop the problem recurring, this is also the natural moment to move to a restricted keyway, where keys cannot be cut at a hardware counter without authorization - see restricted keyway locks and where keys can and cannot be copied in NYC. A "do not duplicate" stamp on an ordinary key is a request, not a control.
Rekeying an apartment cylinder is a short, routine job. A locksmith checks the cylinder is a type that can be rekeyed, pulls it, re-pins it to a new key, refits it, and tests the key from both sides with the door open and closed. Ask for the number of keys you actually need at the time - cutting extras during the visit is simpler than making a second trip. For the detail on pricing, see what rekeying an apartment costs in NYC, and for choosing who does the work, how to choose a locksmith and how to verify a locksmith's license. New York City licenses locksmiths; ours is NYC DCA #1362785-DCA, and any legitimate company will give you theirs without being pushed.
On timing: do it when the move is actually finished, not mid-move. Rekeying while someone is still carrying boxes out produces an awkward situation and often a second visit. If the departure is sudden or the keys are simply gone, treat it as a lost-keys situation instead and act the same day - see what to do about lost apartment keys.
A roommate leaving and a lease ending are different problems. If everyone is moving out, the lock question becomes an end-of-tenancy question: restoring hardware, returning keys and handing the apartment back in the state the lease requires. That is covered separately in the end-of-lease lock guide and, for the next apartment, what to do about locks after moving in.
In most cases you should rekey rather than replace. Rekeying changes the pins inside the existing cylinder so every copy of the old key stops working, which is the actual goal. Replacing the hardware only makes sense if the lock is worn, you are upgrading security, or you want a keyway whose keys cannot be copied.
Check your lease before you do. Many New York leases require consent to alter locks or require that the owner be given a key, and co-op and condo house rules often govern entry door hardware as well. Rekeying is usually an easier conversation than replacing hardware, but have it rather than assume.
No, and this is the situation to get advice on before calling anyone. New York City's unlawful eviction law protects people who lawfully occupy a dwelling, generally including anyone who has lived there 30 days or more, and removing a lawful occupant requires a court rather than a lock change. Speak to a tenant attorney or housing advocate first.
A returned key only accounts for the copies you know about. Keys that lived in a shared apartment for a year or two have usually been duplicated at some point, often for perfectly ordinary reasons. Rekeying ends every copy at once, which collecting keys cannot do.
The building key or fob, the mailbox key, any storage, bike room, laundry or roof keys, smart lock codes and app access, and any spare key held outside the apartment. The entry cylinder is one credential among several, and rekeying it does nothing to the others.
For a standard apartment cylinder it is a short visit rather than a project - the lock stays on the door and only the internals change. Ask for all the keys you need during that visit so a second trip is not required. Call (718) 412-1332 and we can tell you what your lock type needs.